Vitamin C Reduces Exercise-Induced Increases in Cortisol

Study: Supplementary Vitamin C (2 x 500 mg tablets daily) or a matched placebo was administered to 10 and 6 ultramarathon athletes respectively for 7 days prior to participation in a 90 kilometer running event, as well as on the day of the race and for 2 days after its completion. Cortisol levels were measured in both groups immediately after the 90K race.

Results: Cortisol levels were 30% lower immediately post-race in the Vitamin C group as compared to the placebo group levels.